IS 14479 : 1998 ( Reaffirmed 2002 ) Indian Standard ELECTROTECHNICAL COMPATIBILITY OF ELECTRICAL AND ELECTRONIC INSTALLATIONS IN SHIPS - SPECIFICATION KS 33.100;47.020.60 @ BIS 199X BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MAHG NEW DELHI I 10m2 March 1998 Price Group 10 Electrical Equipment and Installations in Ships Sectional Committee, ET 26 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Electrical Equipment and Installations in Ships Sectional Committee had been approved by the Electrotechnical Division Council. Electromagnetic compatibility is the ability of any electrical, radio, radar, communication, control or sonar system to operate satisfactorily in a ship's electromagnetic environment. In preparing this standard assistance has been derived from IEC Rub 533 (1977) issued by the International Electrotechnical Commission. For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1960 `Rules for rounding off numerical values (revised)`. This number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. IS 14479 : 1998 India-n Standard ELECTROTECHNICAL COMPATIBILITY OF ELECTRICAL AND ELECTRONIC INSTALLATIONS IN SHIPS - SPECIFICATION 1 SCOPE 1.1 This standard lays down general principles and practical installation measures to be taken in order to obtain a certain required grade of electromagnetic compatibility from 10 kHz to 30 kHz for all electrical and electronic equipment intended to operate in a ship's electromagnetic environment. It also lays down standard methods for measurement and testing and certain standard requirements. Higher range-of frequency is under consideration. 1.2 This standard applies to electrical and electronic equipment and installations in ships, more specifically to interference suppression apply to components intended for use at voltage exceeding 500 V (dc or ac) between conductors or 250 V (dc) or 290 V (ac, rms) between one conductor and earth. It does not apply to components intended for use at frequencies exceeding 400 Hz. 2 REFERENCES The Indian Standards listed in Annex A are necessary adjuncts to this standard. 3 TYPES OF INSTALLATION 3.1 Installations are classified into five groups, which are either susceptible to or capable of causing electromagnetic interference. 3.J.l Group A Radio communication, radio location, radio navigation and television distribution system, operating with narrow band or sinusoidal radio-frequency (rf.) voltage. 3.1.2 Group B Semiconductor rectifier installation, power conversion plants, generating plants and deck machinery, household appliances and fluorescent lighting, producing broad band continuous spectrum-interference voltages. 3.1.3 Group C Radar and sonar installations operating with pulse energy. 1 3.1.4 Group D Switchgear and controlgear, automatic steering installations gyrocompass navigational instruments, kitchen thermostat and heating plants, producing transient voltages and currents. 3.1.5 Group E Automatic control circuits, micro processor based equipment and ship board personal computers using analogue or digital techniques. 4 GENERAL CODE OF PRACTICE AND REQUIREMENTS 4.1 General Principles of Interference Suppression 4.1.1 Interference (noise) suppression is the reduction of unwanted electromagnetic energy to an acceptable level by means of suppression components and installation measures. 4.1.2 The limits of interference specified in 7.3 to 7.5 assume that the appropriate measures have been taken with sensitive equipment to protect them from the effects of interference. 4.1.3 Conducted interference energy is abated by suppression at the power supply terminals of the equipment generating the interference. 4.1.4 Radiated interference energy is abated by shielding and bonding measures at the interference source by cable shielding and, in certain cases, by complete shielding of the interference source location. 4.2 Measures Relating to the Installation 4.2.1 Abatement of Conducted Interference Energy Conducted interference energy appears in two modes: a) as interference conductors, and voltages between between the each b) as interference voltages conductor and earth. IS 14479 : 1998 Capacitors specifically designed for suppression purposes can often provide adequate attenuation of conducted interference energy. In cases where the interference energy is high, or the interference source impedance is low, combinations of inductors and capacitors can be used. Low-pass filters comprising inductor-capacitor networks having L.T. or IC configurations will, in most cases, reduce the conducted interference energy to an acceptable level. The effects of high level conducted interference energy matlow frequencies can be alleviated by using separate power supplies for interference-producing and interferencesensitive equipment. 4.2.2 Abatement of Radiated Interference Energy 4.3 Measures Relating to the Ship's Structure 4.3.1 Electromagnetic fields emitted by radio transmitters can cause sparking and non-linear effects at imperfect joints of the ship's superstructure (for example, stays, shrouds, wires, etc). The imperfection of joints is caused by corrosion which provides nonlinear transmission paths. 4.3.2 Construction The electrical continuity of all metal parts of the ship's hull or superstructure is always sufficient in the case of welded or riveted constructions. For aluminium constructions, however, welding is preferred. Ahrminium superstructures of steel ships should be bonded to the steel hull of the ship as often as practicable and at least every two metres. 4.3.3 Insulation or Bonding The abatement of the radiated interference energy requires measures in the spacing and shielding of equipment, shielding of cables and, in cases of high radiation intensity, shielding of the interference source location and associated cable runs. 4.2.3 Safety Requirements All interference suppression components used on board ship should conform to the standard specification of the relevant section of this report. They should be of such a construction that the safety of personnel and of the ship is not endangered and should ensure that the performance and reliability of all vital electrical services will not be degraded. 4.2.4 Construction Requirements Consideration shall be given to possible interference problems at an early stage of the design of eqmpment. 4.2.5 Screening of Cables Unless otherwise stated, screening of cables shall consist of: - All rigging should either be insulated from or bonded to the ship's structure in accordance with the following considerations: Stays which are subject to considerable tension, such as mast shrouds and funnel stays, especially in the case of stays on tanker decks, should be bonded. A point near the lower and upper ends of such stays should be solidly earthed, preferably by means of a copper conductor, protected against corrosion and thick enough to withstand mechanical stress. Insulation of stays should be used in the vicinity of the direction-finder loop antenna (aerial) . It should also be used where possible in preference to bonding as it is more reliable and reduces the need for maintenance. 4.3.4 Screening of Compartments Screened rooms may be necessary in certain cases (for example, radio rooms). They should fulfil the following requirements: either a copper, aluminium, lead or a steel, rigid or semi-rigid tube; or a symmetric or asymmetric copper-or steel braid of at least 90 percent coverage by weight of a tube consisting of the same metal, having an internal diameter equal to the internal diameter of the braid and a thickness equal to the diameter of one of the wires forming the braid. 2 a) All bulkheads, floors, deckheads and doors should form a continuous electrical conducting surface. The dc resistance between any two points on the surface should not exceed the value of 0.0 1 ohms. - b) All conduits, pipes, metallic rods and cable screens, etc, entering the room should be bonded at their point of penetration. c>Provision should be made for the housing of suppression filters, if necessary. IS 14479 : 1998 4.3.5 Earthing of Metallic Cabins and Cases When -earthing measures are necessary, the earth connection should be as short as possible, connected directly to the ship's structure and of low r.f. impedance. Low r.f. impedance can best be provided by use of broad metallic straps. Each equipment shall have its own separate earth connection. The connection points should be thoroughly cleaned down to the bare metal which should be protected in an approved manner after assembly. 5 MEASURE RELATING TO INSTALLATIONS OF GROUP A 5.1 Radiated man-made interference energy affecting receiver aerials (antennas) can degrade the YCZformance of radio receivers by: a) distorting the received signal, and Where it is necessary to use single-core cable, the lead and return conductors should be fixed as close to one another as possible and should be so run as to avoid loops of partial loops. Particular care should be taken to segregate cables carrying pulses of high amplitude and power cables supplying units in which such pulses are present. The use of screened cable alone is often inadequate in such cases and it may be necessary to use screened cable run in heavy-gauge conduit. When the radio room is of wholly metallic construction some advantage may be gained by the fitting of suppressors to cables at their point of entry into the room. The modern trend of ship construction is to include radio communication and satellite communication equipment as part of the bridge equipment. As a result of this, there may not be a separate radio room in the ships of the future. 5.3 Setting of Radio Transmitters Radio transmitters should be so installed that the aerial (antenna) feeders between transmitter output and the lead-in insulator are as short as possible. If not precluded by other considerations, metallic screening of the aerial (antenna) feeder of the transmitter in the radio room is a good measure to reduce radiation of r.f. energy in the room. NOTE - The present trend of ship construction is to include radio communication and satellite communication equipment as part of the bridge equipment. As a result of this there may not be a separate radio room in the ship. b) reducing sensitivity due to operation of the receiver automatic gain control circuits. Radio transmitter signals can also impair the correct functioning of the electrical and electronic equipment. 5.2 Radio Room All permanently installed cables within 9 m of any serial system, radio room or direction finder, unless a metal deck or bulkhead intervenes, should be metal sheathed, metal-braided or otherwise adequately screened. In such situations flexible cables should be screened, wherever practicable. It is important that cables other than those feeding services in a radio room should not be installed therein. Cables which must pass through a screened radio room should be run throughout the length within the cabin in a continuous metal conduit or tnmking which shall be bonded to the screening of the cabin at the points of entry and exit. NOTE - It has been found both advantageous and practicable to group supplying services to rooms adjacent to radio receiving installations in a minimum number of well-defined runs. 5.4 Earthing of Radio Transmitters Bonding of radio transmitters requires special attention in order to avoid unwanted coupling to radio receivers and other r.f. sensitive installations. The cabinets of MF and HF transmitters need frequent and good electrical bonding to the ship's metallic structures. This can be easily provided by direct bolting of the cabinet to the metallic foundation or by bridging the shock absorbers with thin metallic straps. 5.5 Earthing of Equipment Each radio equipment shall have its own individual earth connection. The use of a busbar is not recommended as this can lead to unwanted~common-mode coupling effects. 5.6 Layout of Cabling During transmitter 3 operation, all interconnecting When the power converting plant is placed outside the radio roomthe cables connecting converter and radio room should preferably be installed separately from other cables not associated with the radio installation. Similar action may be necessary for certain other cables liable to pick-up interference, for example, auto alarm bells. D/P signal lighting and bridge telephones, unless suitable suppression can be provided. IS 14479: 1998 cables of the radio installation including power supply cables can carry large r.f. currents, and precautions should be taken to reduce possible disturbance to adjacent of sensitive equipment. The use of properly bonded screened cables in the radio installation is a good measure to reduce these effects. 5.7 Bonding of the Screened Cables During transmitter operation, the metallic screens of cables in the radio room can carry high r.f. currents. As proper bonding of the metallic screens of the cables is important, the bonding should preferably be carried out by use of cable glands designed to allow single and reliable bonding of the cable screen (for example, by means of conical inserts). 5.8 Aerials (Antennas) and Aerial (Antenna) Feeders All transmitting and receiving aerials (antennas) should be erected well away from the ship's vertical metallic structure. Transmitting aerials (antennas) must be separated from receiving aerials (antennas) and the direction-finding loops. Satisfactory performance at 2 MHz frequencies may require the siting of the direction-finding loops as high as possible above the bridge. NOTE - The use of screened aerial (antennas) feeders between transmitters and their aerials (antennas) is good measure to improve overall performance and electromagnetic compatibility. R.F. sensitive electronic equipment and cables installed on the upper deck should, therefore, be adequalety screened. Coupling between the radio and the electrical installations can exist via a common mains supply. Improved decoupling between the two installations can be achieved by means of an isolating transformer with earthed metallic screens between the windings in the case of ac supplies, or, by use of a rotary converter with separate windings in the case of dc supplies. When the radio room is of the screened type, interference suppression at the point of outlet on all cables leaving the radio room provides a higher degree of decoupling. 5.10 Internal Communication For internal communication systems and public address systems for conveying voice information and sound reproduction, screened cables with twisted pairs should be used in low level (microphone) signal circuits. The use of cables containing multiple cores not laid up in twisted pair formation should be avoided. The cables should have a non-conductive outer sheathing. The metallic screens of the cables should be earthed at one end only (usually the amplifier end) in order to avoid the forming of inducting loops. This measure is quite the opposite to the requirements given for power circuits, where earthing at both ends of the cable is necessary. 5.11 Limits of Unwanted Electrical installations r.f. Voltages in Ship's All receiving aerial (antenna) should be metalscreened over their complete length. In special cases, coaxial types of aerial (antenna) feeders should be of doubled-screened construction or should run in seamless metallic conducts. It is also mentioned that transmitting aerial (antennas) must be separated from receiving aerials (antennas) and the direction finding loop. In this case also, it is very important to specify the minimum separation required to be maintained between the transmitting aerial and the receiver aerial. 5.9 Decoupling of the Radio Transmitter from Other Electronic Installations The radio-installation radiates high power r.f. energy via the associated transmitting aerials (antennas) which can influence all electronic installations and cable runs on the upper deck, especially in the vicinity of the transmitting aerials (antennas). 4 The unwanted r.f. voltage measured at the power supply terminals of the radio transmitter at the carrier and the harmonic frequencies should not exceed: 10 mV or 80 db (pV) In the frequency range of 150 kHz to 3 0 MHz (These figures may be subjects to modification if practical requirements deviate from the given values.) The unwanted r.f. voltage shall be measured in accordance with the method given in 10.1.2 at a specified point outside the radio room when sequentially each of the radio transmitters working in the frequency range 0.15 MHz to 30 MHz transmits successively at full power. The aerial (antenna) output of the transmitter concerned shall, however, be IS 14479 : 1998 connected to a non-radiating dummy aerial (antenna) in order to avoid any induction of the cables by radiated rf. energy. 5.12 Limits of Coupling Attenuation currents above 250 A, for which special requirements are given in 28 of IS 10242 (Part 3/Set 12). Mains supply equipment should have the lead and return supply wires run together along the same route. Power cables need not be screened, but screening is advisable in the following cases: on the open deck; in the vicinity of the radio room; in ship'sinstallations in the power plant. using thyristor control According to permissible interference field strength values and assuming the maximum mains interference voltage specified in 6.2 the coupling attenuation between the mains network and a reference aerial (antenna) of 1 m effective length should have a minimum value of 70 db measured in the 30 kHz to 30 MHz frequency range by the method given in 10.2. 5.13 Limits of Mains -- Interference for Receivers Immunity The screens of power cables should be earthed as often as possible and at least at each end. Careful attention should be given to all those enclosures and machines which contain semiconductor components and switching circuits. High-current circuits do not, in general, allow the insertion of inductors and in these cases, screened power cables should be used. All external wiring connected to the interference source should be included in the interference suppression measures. Care should be taken when -applying suppression to semiconductor control circuits to avoid degrading the performance of the circuits. 6.2 Limits of Interference Terminal (see Fig. 1) Voltage at the Mains Ships radio receivers should be adequately protected against impairment of their performance caused by interference energy entering the receiver via the mains leads. The mains immunity A4is defined as: M= 20 log 10 Mains-injected interference voltage Input signal voltage Both signals producing an equal receiver output. Its minimum value should be 70 dB. These figures may be subject to modification if practical requirements deviate from given values over the entire frequency range [see IS 12193 (Part 2)]. The receiver can be fitted with an additional mains suppression filter, if necessary, and in this case, the mains interference immunity figures supply to the receiver filter combination. 6 MEASURE RELATING TO INSTALLATIONS OF GROUP B 6.J Part of the equipment generating broadband interference energy includes ac and dc commutator motors; another part of this group of increasing importance consists of semiconductor rectifier installations and regulating systems designed to drive and control dc motors, generators, etc. Semiconductor systems in particular can generate high levels of interference in the frequency ranges below about 300 kHz. Inthe case where single-core cables have to be used, the cables are to be laid as close as possible to each other. Power cables should run as close as possible to the metallic hull or hull head;-excepting cables carrying 5 The permitted levels of interference voltage are different for narrowband and broadband interference. a) Narrowband 30 MHz Interference Voltage IO kHz- From 100 dB (pv) at 10 kHz, decreasing continuously to 60 dB (V) at 1 MHz and 60 dB (pv) between 1 MHz and 30 MHz (to be measured by a calibrated selected r.f. voltmeter). b) Rroadband 150 kHz Interference Voltage 10 kH.z- From 90 at 10 kHz, decreasing continuously to 56 dB (pV) at 150 kHz to be measured by an equal-peak detector ha\-ing a bandwidth of 200 kHz. c) Broadband Interference 3 0 MHz Voltage 150 kHz- From 76 dB at 150 kHz, decreasing continuously to 60 dB (pv) at 1 MHz and 60 dB (pv) between 1 MHz and 30 MHz, to be measured by a quasi-peak detector having a bandwidth of 9 MHz. IS 14479 " 1998 The terminal interference voltage shall be measured as described in 10.1.1 and 10.1.2. 6.3 Limits of the Interference Current at the Mains Cables ( see Fig. 1 ) continuously to 26 dI3 (pV) at 50 kHz. (To be measured by a quasi-peak detector having a bandwidth of 200 Hz). c>Broadband 30 MHz Interference Current 150 kHz- The permitted levels of interference current are different for narrowband and broadband interference. 4 Narrowband 30 MHz Interference Current IO kHz- From 90 dB (nV) at 10 kHz, decreasing continuously to 17 dB (uV) at 1 MHz 17 dB (uV) between 1 kHz and 30 MHz . (To be measured by a calibrated r.f. current probe). From 46 dB at 150 kHz, decreasing continuously to 17 dB (nV) at 1 kHz, and 17 dB (pV) between 1 MHz and 30 kHz. (To be measured by a quasi-peak detector having a bandwidth of 9 kHz). Interference current shall be measured as described in 10.1.3. 6.4 Limits of Coupling Attenuation Reference should be made to the requirements laid down in 5.12. b) Broadband 150 kHz Interference Current 10 kHz- From 70 dB at 10 (pV) kHz decreasing fINTERFERENCE -------INTERFERENCE VOLTAGE CURRENT LIMITS LIMITS (MHz) FIG. 1 INTERFERENCE VOI,TAGE AND CURRENT LIMITS 6 IS 14479 : 1998 6.5 Limits of Immunity to Transients Semiconductor control shall be capable of withstanding symmetrically and asymmetrically induced transients in compliance with the test described in 10.3.6. 7 MEA!XlRE RELATING TO INSTALLATIONS OF GROUP C 7.1 Radar and sonar equipment utilize electrical pulse energy. This pulse energy can give rise to interference in other installations, conversely the equipment itself is subject to interferences. 7.2 Great care must be taken to separate pulsecarrying cables from cables associated with other installation. The length of waveguides or feeder cables in radar installations should be kept as short as possible. Proper earthing of all equipment including the waveguides is an indispensable measure for reducing mutual interference between radar and radio installations. Pulse-carrying cables should be shielded; the use of steel conduits or the use of double-screened cables is preferred in the case of sonar installations. 7.3 Limits of Terminal Interference Voltage and Currents Reference should be made to the requirements laid down in 6.2 to 6.5. 7.4 Limits of Coupling Attenuation Reference should be made to the requirements laid down in 5.12. 7.5 Limits of Immunity Radar and sonar equipment comprising interferencesensitive circuits should be protected against impairment of proper functioning caused by electromagnetic interference. Testing of the interference immunity should be carried out in compliance with 10.3. Standard test procedures are indicated in 10.3.3 and 10.3.4. 8 MEASURES RELATING To INSTALLATIONS OF GROUP D 8.1 This clause deals with sudden changes in the steady electrical state due to switching operations which can cause interference in sensitive equipment and circuits which are sensitive to pulses such as digital control circuits and television entertainment equipment. 8.2 In general, small transients occurring at 7 irregular widely spaced intervals can be ignored. Switching of reactive circuits can provide high peak transient which need adequate abatement measures. Large transient should be controlled by the use of non-linear resistors or other suitable measures. Broadband suppression can be provided by the use of suitable filters. 8.3 Signal cables of interference-sensitive installations should have a non-conducting outer sheathing in order to prevent resistive coupling with ship's hull at low frequencies. Preference is to be given to twisted pair cables in order to reduce crosstalk between different circuits. The metallic screen of the cables should be earthed at one end only. 8.4 Common return wires in signal and control cables should be avoided. 8.5 Telecommunication circuits having a mean level difference of more than 40 dB (pV) should not run in the same cable. 8.6 Segregation of cables carrying interferencesensitive circuits is an adequate measure to reduce interference effects. 8.7 Limitsof Transient Voltages land Currents These limits cannot be defined. 8.8 Limits of Immunity to Transients Semiconductor control equipment shall be capable of withstanding symmetrically and asymmetrically induced transients, in compliance with the test described in 10.3.5. 9 MEASURE RELATING TO INSTALLATIONS OF GROUP E 9.1 This clause is concerned with data acquisition and control systemtransmitting analogue and digital signals between sensors, processors, control and ancillary equipment, associated with these systems are semiconductor switching, motor drives, relays and other interference-producing equipment, for which reference should be made to 6 and 8. The main group comprises equipment which is both susceptible to and capable of generating electrical interference. 9.2 System Design To reduce electromagnetic compatibility problems, the following standard requirements in respect of system design shall be implemented where applicable and necessary to enable the equipment to withstand the tests specified in 9.6 to 9.8 and 10.3: Is 14479: 1998 a) Equipment should be insensitive to signals outside the designed frequency range, that is, the minimum bandwidth consistent with system requirements should be used. n>Interference can enter or leave an equipment via the power lines or any cable penetrations. Appropriate suppression measures should be applied at these points of entry or exit. b) High-level signal, low-speed sampling systems are preferred and should be specified whenever system requirements permit. cl Low-level signal transmission should be avoided or the signal level raised by preamplifiers located closely adjacent to the sensors. impedance as possible to reduce the effects of pickup due to cable coupling. P) Processing equipment can radiate unacceptable interference and conversely may be sensitire to radiated interference from local sources including the ship's transmitters. Shielding should be applied, if necessary, in these cases. 9.3 Special Amplifiers Precautions with Measurement d) Circuits should be designed with as low an e) Asymmetric or common mode potentials typically 1.2 V with occasional transients of tens or even hundreds of volts can exist in ships. Measurement amplifiers, particularly those concerned with precise measurement of low-level signals, should have adequate rejection against this mode of interference coupling. 0 Balanced differential amplifiers and guardring techniques significantly increase the rejection of asymmetrical induced interference and should be considered. g) Analogue-to-digital concerto's should preferably be of the integrating type. In a ship installation, the signal lines of measurement amplifiers are subjected to electric and magnetic fields from local interference sources, the frequency range extending from power frequencies to radio frequencies. Asymmetric or common mode potentials can therefore be enclosed in each line of the signal pair relative to the ship's metallic structure. In a perfectly balanced system, these potentials are equal in magnitude and sign and no potential difference can exist between the lines, that is, there is no resultant symmetric or serial mode component. In practice, such balance is difficult to achieve over a sufficiently wide frequency range and the resulting symmetric component is applied together with the measurement signal to the amplifier input. Suitable measure (for example, filtering) should be incorporated in the design to reduce the effect of this type of interference to an acceptable level. To verify that the measures taken are adequate, the tests specified in 9.7 should be applied. 9.4 Cable Installation If circuit configuration precludes the use of adequate suppression or counter measure, particular attention should be paid to cable selection and installation. The following standard requirements are a guide of general nature and shall be implemented where appropriate: a) Signal pairs carrying low-level signals at sonic and supersonic frequencies should be tightly twisted and screened throughout their length, screens should be electrically continuous, earthed at one point only and should never be used as a signal path. The earthing point should be at the sensor end when this is earthed, or at the processor when the sensors are floating. To prevent resistive with the ship's hull, an insulated outer sheath appropriate to the 8 h) Zero volt lines if run between equipment in a system should be earthed at one point only. This point should be accessible for ease of checking for fortuitous earths. In cases where single point earthing is impracticable, transformers or optical couplers can provide the necessary isolation between circuits. j) Cable runs between and within equipment should be carefully planned, and separation, twisting and screening techniques exploited. k) Transformers provided with earthed screens between core and nearest winding and betweert primaries and secondaries should be used if necessary to isolate equipment from interference present in the ship's power supplies. m) The use of electrical motors in control circuits should be minimized, but where their use is necessary they should be suitably suppressed prior to inclusion in the system. IS 14479 : 1998 environment should surround the screen. in 6.2 to 6.5. 9.? Limits of Immunity Equipment should he capable of withstanding the tests specified in 10.3.3 lo 10.3.6. 9.g Additional Amplifiers Tests for Measurement Induced / b) An exception to the single point earthing of `signal' cable sceens can occur when the length of cable exceeds l/8 waveleragth of an interfering signal. In this case it may he necessary to earth the screen at both ends, the connectionsto frame being made on the outer surface of the enclosure, that is, the screen must not penetrate the enclosure. cl Where crible runs pass through cormectors at junctton boxes, pins should be provided to carry the screens. 9.8, I Rcj'echion of Asymmetrical@ Interference d) Signal cables should be separated from power and control cables by a minimum distance of 500~mmand parallel runs avoided. Ifsignal cabies have to pass near such cables. they should do so far a minimum distance (less than 5 m) and crossings made at right angles or at a minimum distance of 200 mm. As far as practicable, cables carrying analogue signals should be separated from cables carrying digital signals and par&e! runs avoided. If adequate separation cannot be achieved, cables carryiug low-level analogue signals shouldbe run in steel conduits or metal cable trays. All conduits and trays should be bonded together and connected to the hull. Cables carrying high-level digital signals (a magnitude of volts), although not usually susceptible can cause interference and should be screened. To acheive optimum screening efficiency, it may be necessary to earth the screens at both ends. 9.5 Bonding and Earthing Connections to equipment frames should be such that reliable and lasting electrical connections are made. All contact surfaces should be clean and free from paint, grease and oxides. Metal type not braided is preferred for bonding and the shortest possible length should be used. The type should have length to width ratio not exceeding 5: 1. The bonding and earthing, and earthingpolicy adopted should avoid the formation of loops. 9.6 Limits of Interference Voltages and Currents Reference is made to the requirements laid down 9 The test should be conducted in accordance with the typical arrangement of Fig. 2. The signal generator used as a disturbing signal source should have a source impedance of 50 ohms and the amplitude adjusted to give an output of 1 V rms into a 50 ohms load. The output should be modulated to a depth of 30 percent at a frequency of 1 kHz in the frequency range 10 kHz to 30 MHz. With input signal to the amplifier set to give a convenient reference level at the output, the disturbing signal source should be swept over the frequency range 50 Hz to 30 MHz and the output monitored for deviations in the set frequency level. The rejection is deemed to be adequate if no deviations in excess of the design tolerances of the test sample are noted. 9.8.2 Rejection of Symmetrically Interference Induced The test shall be conducted in accordance with the typical arrangement of Fig. 3 with the input signal set to give a convenient reference level at the output, the disturbing signals from the signal source should be applied. The rejection is deemed to be adequate if no deviation in excess of the design tolerances of the test sample are noted when: a) A level of 1 V rms (50 ohms load) is applied at power frequency from the disturbing source. b) A level of 10 mV [ 8OdE3(pV) (50 ohms load)] is applied at frequencies in the range 10 kHz from the disturbing source. The source to be modulated at a depth of 30 percent at a frequency of 1 kHz. NOTE - As an alternative to setting a reference level at the output, the input terminals of the amplifier can be terminated in an impedance equal to the rated terminating value. The level of disturbing signal ..t the output should not be in excess of the rated levels for the system. TEST SAMPLE SET r LEVEL INDICATOR B L % INPUT SIGNAL SOURCE 0 0, A 0 0 V DISTURBING SIGNAL SOURCE E NOTF - C, = Cl Impedance c 5 fl at injected frequency. - FIO. 2 TEST ARRkNl(iEMENT ASYMMETRIC INJECIION TEST SAMPLE INPUT SIGNAL SOURCE d 0 I SET LEVEL INDICATOR IS 14479 : 1998 10 METHODS OF MEASUREMENT AND SUPPRESSION TECHNIQUES 10.1 Terminal Interference Voltages and Currents NOTE - The measuring methods are related to known and generally accepted techniques as far as possible. Reference is made to standard methods, if available. of an apropriate r.f. voltmeter at the point of injection Suitable measuring frequencies should be chosen in each of the ship's radio navigation and radio-communication bands between 70 kHz and 25 MHz. The field strength, Eat the position of the receiving aerial (antenna) is measured by means of a calibrated rod aerial (antenna) and a measuring set. An example of a rod aerial (antenna) and a corresponding aerial (antenna) factor F,. Known field strength in open field Fa = Voltage at the input of the measuring set is given in Fig. 4 and Fig. 5. For all other types of rod aerial (antenna) (length between 1 m and 4 A). the aerial (antenna) factor F, should be established in open field. The aerial (antenna) decoupling factor C is calculated from the injection voltage U,, the receiver voltage U, and the aerial (antenna) factor F, as follows: C(dB) - 20 log U, - 20 log U, - 20 log F, Ship's aerials (antennas) at the position of measurement should be received disconnected from the aerial (antenna) cable and receivers. The rod aerial (antenna) should be away as far as possible (at least 2 m) from large vertical parts. The base of the rod aerial (antenna) should be earthed at the metal superstructure by means of a short earth lead. Earthing should also be provided for the measuring set and the interconnecting coaxial cable, which should have the same characteristic impedance as the input impedance of the measuring set. 10.3 Immunity to Interference 10.3.1 The purpose of immunity testing is to verify that equipment will function satisfactorily when its case, external cables and ancillary equipment are subjected to electrical interference voltages and fields. In the following clauses, tests are proposed with suggested degree of severity designed to cover a wide range of equipment. 10.3.2 Selection Performances of Tests and Grade of 10.1.1 Terminal Broadband Interference Voltage Broadband interference produced by interference sources shall be measured at the mains terminals of those sources. The broadband interference voltage shall be measured in accordance with the standard methoas laid down in IS 10052 (Part 1). NOTE - All broadband interference voltage measurements should normally be carried out with an artificialmains network inserted to isolate the test sample from the supply mains. In cases where the test sample consumes high currents (above 25 A), the artificial-mains network may be omitted. 10.1.2 Network Interference Voltage For the measurement of narrowband interference voltage, the measuring apparatus (see 10.1.1) can be replaced by a calibrated receiver. For the measurement of narrowband interference voltage (caused, for example, by a radio transmitter) at a specified point in the mains network, the artificial mains network is omitted and the r.f. voltage is measured between each of the supply lines and earth by use of a calibrated high impedance probe connected to an interference measuring set. 10.1.3 Interference Current in Cables In this type of measurement, the interference source is usually connected to the mains network without inserting an artificial mains network, the interference current is measured by means of a calibrated current probe enclosing the mains lead or cable and connected to a measuring setin aGcordance with the requirements given in 10.1.1. 10.2 Aerial (Antenna) Coupling Factor Between the Mains Network and the Radio Receiving Installations 10.2.1 An r.f. generator with output voltage (Ug) of at least V preferably amplitude modulated, is connected via an isolating capacitor of 0.1 pF between the injection point and the nearest part of the hull (earth). The injection point should be at the main switch-board, or at any convenient mains terminal as near as possible to the mains switchboard. The injected r.f. voltage should be measured by means 11 Tests should be selected from these clauses to meet the specific requirements of a particular system. No malfunction, performance degradation or change in indication as defined by the design specification of the test should be produced when the tests are -+-7x REMOVABLE UPPER PART ROD AERIAL (ANTENNA) LOW LOSS b-/ MATERIAL //-h COAXIAL dA8LE =5011 or75 R INSULATlNG MEASURING R 0) r EARTHING POINT COAXIAL CABLE OF DEiAll A All dimenions in millimetres. Fra. 4 ROD AERIAL(ANTENNA) FOR COUPLING AITENUATION lv&AsummhT IS 14479: 1998 (dB) 20 log ,oFa 25 03 1 2 f- 3 45 10 20 30 &Hz) FIG. 5 AERIAL (ANTENNA) FACTOR F, OFROD AEKIAL (ANTENNA) AKORDING TO FICXJRE 4 applied to a sample. NOTE-these tests Aerials (antenna) are specifically excluded from The signal generator shall be correctly terminated and shall be connected to the cable under test via a capacitor having an impedance less than 5 ohms at the measurement frequency. An isolating network may, if necessary, be connected in series with the supply line to isolate a possible low impedance of the supply line to earth. The signal generator should supply a 30 percent modulated test signal capable of being swept over the frequency range 10 kHz to 30 MHz. For power supply line injection, the level of the test signal should continuously rise from 0.1 V at the upper end to 10 kHz ( see Fig. 8 ). For cables other than power supply cables, the level of the injected signal should be 0.1 V over t?l.: entire frequency range. 13 10.3.3 Injection into Earth Lead, from 10 kHz Coupling between equipment and systems can occur due to a common earth impedance. The test is designed to verify that the sample does not respond to this mode of coupling. The sample should be isolated from the earth plane and its earth lead taken to the earth plane via the secondary of the isolation transformer of Fig. 6. The apparatus is used to inject voltages having an open circuit value of 1 V rms. 10.3.4 Conducted 10 kHz to 30 kHz Radio-Frequency Voltages from The test shall be in accordance arrangement of Fig. 7. with the typical ---_---_-----SIGNAL GENERATOR 1 PQWER SUPPLY I I LAIING TRANSFORM ---__--------TEST SAMPLE I NOTES 1 Signal generator shall have ah output impedance not exceeding 1 R 2 Isolating transformer shall carry all currents without saturation. 3 The a.c. ioltmeter shall indicate the open circuit voltage. FIG. 6 TYPICAL ARRANGEMENTS FOR TESTS- I ~MCONDtiC~D~RFERENCEFRoM10k~TO50~ IS 14479: 1998 POWER ? SUPPLY ? 0 ,/" f 6 ISOLATION __-.. NETWORK,,-" _ .__. ..~ ' P 0 SIGNAL GENERATOR ADAPTER NETWORK TEST SAMPLE FIG.7 TYPICAL ARRANGEMEM FOR TESTS - IMMUNITY TO CONDUCED INTERFERENCE FROM 20 kHz TO 100 MHz 100 - 80 ' 0.01 0.1 1.o 10.0 1CIO MHz SIGNAL FREQUENCY FIG. 8 SIGNAL LEVELS FOR TESTS FOR IMMUNITY TOCONDUCTED INTERFERENCE 15 IS 14479: 1998 10.3.5 Transients on Power Lines Power supply lines are subject to occasional high amplitude short duration transient voltage. The test is designed to verify that equipment will function satisfactorily in the presence of these disturbances. The test shall be in accordance with the arrangement of Fig. 9 and the transient should have theresultant waveform shown in Fig. 10. The transient wave with a maximum amplitude of 400 V (V, = 500 V), can be originated from a reference circuit of the form given in Fig. 11. The following operation: values are proposed for the test resultant large r.f. current will cause radiation of interference. Special types of capacitors known as feed-through or lead-in capacitors can be connected directly into the line. The excellent attenuation characteristics of these capacitors can only be obtained if they are properly installed and the manufacturer's requirements regarding installation shall be strictly followed. If the grade of interference attenuation provided by capacitors is inadequate, inductor/capacitor network of suitable design should be used. Care should be taken to prevent possible undue voltage drops and overheating of any inductors used in the network. 10.5 Measures to Improve Equipment to Interferences the Immunity of U, = 1 000 V ([J,,, = 400 V) T,= 10 s T,= C, (I?,-+-&) In the case of low voltage power lines, the maximum value of the transient waveform should be limited to 100 V 10.3.6 Circulating Screens 10.5.1 Internationally agreed electromagnetic interference level at the mains terminals of electrical equipment are related to the influence of its effect on the recession of radiotelephony. qfInterconnecting Currents in Metalwork Cables and In view of this, certain concessions have been made in that single and short duration clicks and buzzes may be ignored, as the reception of radiotelephony will not be impaired by the loss of single syllables. Signal circuits operating with short pulses can, however, be seriously disturbed in their proper operation even if man-made noise voltages are suppressed to the fixed levels. The immunity of electronic installations sensitive to discontinuous interference or continuous interference below the permitted levels should, therefore, be adapted to the electromagnetic environmental conditions on board ship. This can best be accomplished by system planning covering the whole installation for instance, layout of interference-sensitive circuits, amplification of the signals at the source, separation of the power supply, shielding of equipment, use of doublescreened twisted cables, proper earthing of equipment and cable screens. 11 VITAL INTERFERENCE COMPONENTS SUPPRESSION Circulating currents flowing through cabinet metalwork and screens of interconnecting cables can induce interference into sensitive circuits within the cabinet. To verify that equipment is not sensitive to this mode of coupling, radio-frequency currents having an rms value of 100 mA shall be passed through the cabinet metalwork of the sample. The current shall be passed from one corner to all other corners of the cabinet in turn, and the signal source swept over the range 15 kHz to 30 MHz. Where units are interconnected by screened cables the current should also be passed through the screen of each cable in turn. A suggested test arrangement for radio frequencies is shown in Fig. 12. Each winding of the ferrite cored bifilar wound transmission line transformer shall have an inductance of 1 mH. 10.4 Suppression Measures 10.4.1 Capacitors are used to provide a low impedance path for interference currents and are intended effectively to short-circuit the interferences source at radio frequencies. If the capacitors are not connected as close as possible to the source, the 16 11.1 Capacitors, inductors, filters and fuses for capacitors, are certain interference suppression components, whose failure could seriously endanger the safety of the ship either by: a) permitting interference, which would disorganize radio or electronic system on board, or IS 14479: 1998 POWER TRANSIENT GENERATOR SUPPLY (A) =SYMYETRlCAL TYPE 9A Symmetrical Type l I I I I POWER TRANSIENT GENERATOR SUPPLY (R) =~MXTRICAL TYPE 9B AsymmetricalType FIG. 9 TYPICAL ARRANGEMENT FOR TESTS IMMUNITY TOINJECTED TRANSIENTS 17 IS 14479: 1998 fo= RELATIVE VOLTAGE FIG. 10 WAVEFORM FOR TESTFOR IMMUNITY TOTRANSIENTS FIG. 11 REFERENCE CIRCUIT POWER SUPPLY TEST SAMPLE I=100 mA ' FIG. 12 TESTARRANGEMENI FOR RADIOFREQUENCIES b) upsetting or stopping the operation of vital electrical equipment (for example, steering motors or navigational aids) of which the components are fitted. It is essential for all suppression components which may be used as above to be of the highest possible 18 quality. In this connection, experience should be taken short-term reliability testing the manufacturer's into consideration as is not infallible. Capacitors for shipboard use which do not fall into either of the above categories should meet the conditions outlined in IS 3723 series. IS 14479 : 1998 The following clauses apply to component intended for use with electrical devices on board ship up to 500 V dc or 500 V ac (rms) between conductors or 250 V dc or 290 V dc (rms) between one conductor and earth at frequencies not exceeding 400 Hz. The requirements and test methods of these interference suppression component are intended to be used to: 2+500 across the shortest gap. The creepage distance between any terminals or between any live terminals and the metal housing shall~be not less than: u 2 + 250 mm across the surface of the insulant, where C' is the peak value of the rated working voltage. If the insulating part contains a groove less than 1 mm wide, the creepage distance shall be measured across the width of the groove and not over its surface. When calculating the necessary clearance, fractions of a millimetre shall be counted as 1 mm. 11.6 Nominal Voltages Preferred nominal voltage values of components are: ac : 127 V, 250 V, 380 V, 500 V (rms); and dc : 50 V, 160 V, 250 V, 500 V. u mm 4 obtain electromagnetic compatibility between equipment and systems on board ship when component meeting the requirements are fitted, electrical device impaired, and of all vital on board ship is not b) ensure that the performance c) ensure that the safety of the personnel and of the ship is not endangered. 11.2 Operating Conditions All components shall be suitable for continuous operation in tropical and arctic conditions with a saturated salt-laden atmosphere. Components suitable for present, for carbon dust, fitted to devices or machines shall be any unusual conditions that may be example, the existence of copper or oil vapour, etc. - 11.7 Nominal Temperature Ranges Preferred nominal operating temperature ranges are: 25'C to-_* 85°C 55°C to + 85°C Components fitted externally shall be housed in substantial case to afford mechanical protection. 11.3 Terminals and Terminal Connections Terminal connections shall be of solder-coated or tinned wire suitable insulated or shall be ofthe screw or soldering type. Their cross-sectional area shall be not less than 0.5 m* and where they are intended to form part of the main supply circuit to the appliance, their cross-section shall be adequate to carry current at a current density not exceeding 300 A/cm*. Where a terminal has the form of a screw and nut, a locking device shall be provided. 11.4 Internal Connections 55°C to +loo"c 11.8 Classes of Test The following classes of test shall be carried out: a) Routine tests on all components carried out by the manufacturer to verify the components meet ~the requirements of 12.4. b) Type tests of 12.5 on pre-production samples to verify design. 12 SPECIAL REQUIREMENTS FOR CAPACITORS 12.1 Construction Screwed connections shall not be used for internal connections of components of filters which are hermetically sealed. 11.5 Creepage Distances and Air Clearances The clearance between any terminals of a component or between any live terminal and the metal housing shall be not less than 19 The connections and mounting arrangements of a capacitor shall be such that it is unnecessary to apply heat to any metallic case when fixing or connecting. IS 14479 : 1998 12.2 Marking Marking shall be in accordance with IS 3723 (Part I). The year of manufacture shall be clearly indicated. Use of code is not permitted. 12.3 Self-Inductance All suppression capacitor minimum self-inductance. 12.4 Routine Tests 12.4.1 Voltugt? Proof Ml capacitors shall be subjected to high-voltage tests then be made in the following order: Lot A Power factor Coupling impedance characteristics, insertion loss and inductance shall be designed for Robustness of terminations Soldering Vibration Bumping Container sealing Rapid change of temperature Climatic sequence; dry heat (first cycle) by the application of voltages for 1 s as set out in the following table, these voltages bei~rgapplied across the points set out in IS 3723 (Part 13. Capacitors Between Termination Between lhe Qther Test Point For ac 6 U, (ac) or 2 U, + 1500 V (ac) 9 & (dc) 8 u, (dc) 2 V, + 1500 V (dc) -- damp heat (accelerated) cold damp heat cycles ) For dc ( accelerated) ( remaining [JR = rated voltage in volts. Final measurements. Lot B There shall be no permanent breakdown or flashover. 12.4.2 Capacitance The capacitance shall be measured as described in IS 3723 (Part l), and shall be within i 20 percent of the rated value. 12.4.3 Insulation Resistance Damp heat (long term exposure). Lot C Endurance Salt atmosphere. Lot D The insulation resistance shall be measured as described in IS 3723 (Part 1) and shall be within the limits set out therein. 12.5 Qpe Tests The requirements of IS 3723 (Part 1) shallbe met. 12.5.1 Schedule of Type Tests Discharge inception Mould growth. 12.5.2 Standard Conditions of Testing The standard conditions of tt.;ting as set out in IS 3723 (Part 1) shall apply. 12.53 Power Factor Except for metal foil capacitors, the loss angle shall not exceed 0.01 with frequency between 50 Hz and 2 000 be relaxed at the user's discretion if vity ceramic used. tangent of the measured at a Hz. This may high permitti- All capacitors provided for the type tests shall have passed the routine tests in 12.4. They shall then be checked in accordance with IS 3723 (Part 1). The initial and final measurements for capacitance and insulation resistance shall be made and recorded. Voltage proof tests shall be carried out on all samples in accordance with 12.4.1. These capacitors shall then be grouped into four lots in accordance with the-provisions of IS 3723 (Part l), and labelled lots A, B, C and D. Tests shall 20 12.54 Coupling Impedance Characteristic Insertion Loss and Self-Inductance Tests shall be made in accordance with IS 3723 IS 14479 : 1998 (Part 1) and the results recorded. 12.5.5 Robustness of Terminations according to out and the 12.5.13 Damp Heat (Accelerated) (First Cycle) Tests for robustness of terminations IS 3723 (Part 1) shall be carried requirements met. 12.-5.6 Soldering The capacitors shall be subjected to the first cycle damp heat procedure of IS 9000 (Part S/Set 1 and 2) for one cycle of 24 h. After recovery, the capacitors shall be subjected immediately to the cold test. 12.5.14 Cold The capacitors shall be subjected to test of IS 9000 (Part 2Kec 1 to 4) using the appropriate degree of severity. 12.5.15 Damp Heat (Accelerated) Cycles) (Remaining The soldering terminations of capacitors, if any, shall meet the requirements of IS 3723 (Part 1). Alternatively, the solder globule test of IS 9000 (Part 181 Set 1 to 3) shall be complied with. 12.5.7 Mbration The capacitors shall meet the vibration requirements of IS 9000 (Part 8) with a specified severity. 12.5.8 Damping The capacitors shall meet the requirements IS 9000 (Part 7/Set 1 to 5). 12.5.9 Container Sealing The container sealing of capacitors shall be tested according to IS 9000 (Part lS/Sec 1 to 9) using appropriate methods. There shall be no visible bubbling or seepage. Category Minimum RC Product for Capacitors with Rated Capacitance Exceeding 0.33 pF 2 000 s of The capacitors shall be subjected to the remaining cycles of the damp heat procedure of IS 9000 (Part S/Set 1 and 2) for five cycles of 24 h. 12.5.16 Final Measurements After recovery from the proceeding tests, the capacitors shall be visually examined. There shall be no visible damage and the marking shall be legible. The insulation resistance of the capacitors shall be measured and shall fulfll the foFlowing requirements: Between Terminations Minimum Resistance for Capacitors with Rated Capacitance Up to and Including 0.33 pF 6 000 M Minimum Resistance Between Termination and Case -1-156 6 000 M 12.5.10 Rapid Change of Temperature The capacitors shall be subjected to the tests for rapid change of temperature set out in IS 9000 (Part 14/Set 1 to 3) and meet the requirements thereof. 12.5.11 Climatic Sequence and Initial Measurements The capacitors shall be subjected to the following sequence tests: The capacitance and insulation resistance shall first be measured and recorded. The capacitance and insulation resistance shall Iirst be measured and recorded. 12.5.12 Dry Heat The capacitors shall be subjected to dry heat test of IS 9000 (Part 3/&x 1 to 5), using the appropriate degree of severity. 21 The capacitors shall be measured 24 f 4 h after the conclusion of the climatic sequence unless it can be demonstrated that stability is reached earlier. The change of capacitance, compared with the value measured in 12.4.2 shall not exceed 5 percent. 12.5.17 Damp Heat (Long-Term Exposure) The capacitors shall be subjected to damp heat (steady state) test laid down in IS 9000 (Part 4) for 58 days. At the conclusion of the test, the insulation resistance shall be measured and requirements of 12.5.16 shall be met. 12.5.18 Endurance The capacitors shall be subjected to the endurance tests laid down in IS 3732 (Part 1). The insulation resistance as well as the capacitance shall be checked at the end of 24 h. The capacitors shall then be IS 14479 : 1998 subjected to two cycles of accelerated damp heat according to the procedure given in IS 9000 (Part YSec 1 and 2) and the above measurement repeated. The capacitors shall then withstand the voltage proof test given in 12.4.1. At the conclusion of the test, the insulation resistance shall be measured and the requirements of 12.5.16 shall be met. 12.5.19 Salt Atmosphere The zapacitors shall be subjected to salt mist test according to IS 9000 (Part 11). Final measurements shall be recorded and the capacitor examined for signs of corrosion ~which should not be such that design performance is impaired. 12.5.20 Discharge Inception cl nominal voltage, d) maximum operating temperature in free air, e) Manufacturer's name or trade-mark, f) Type designation or catalogue number, and .a Reference to this report. 13.4 Routine Tests 13.4.1 Self-Inductance The self-inductance shall be measured under `no load' conditions. The measured self-inductance shall be within 25 percent af the nominal self-inductance. 13.4.2 Voltage Proof All inductors shall be subjected to high-voltage tests by application of a test voltage at 50 Hz or 60 Hz for a duration of 1 s applied between: a) all possible pairs of live parts or windings; and b) all live parts and any other metallic parts such as the core, case or mounting screws. The test voltages shall be: 2 kV (rms) for inductors voltages below 380 V, and with nominal The capacitors shall be connected in turn to a discharge detector and each shall have 50 Hz or 62 a.c. voltage of three times the rated voltage applied for 1 m. This voltage shall then be reduced without interruption to the rated voltage of the capacitor and then maintained for 10 min. At the end of this time, the voltage shall be increased, without interruption to l-2 times the rated voltage. Any discharge shall be less than 30 PC. 12.5.21 Mould Growth The capacitors shall be subjected to mould growth test according to IS 9000 (Part 10). Final measurements shall be recorded and the capacitor examined for signs of mould growth which should not be such that design performance is impaired. 13 SPECIAL REQUIREMENTS INDUCTORS 13.1 Construction The inductor shall be designed for minimum voltage drop, self-capacitance, and `g', at self-resonance unless otherwise specified. 13.2 Insulation The material used for any insulation purpose shall be Class E or better. 13.3 Marking The following information is to be given: a) nominal self-inductance, b) nominal current, 22 FOR 2.5 kV (rms) for inductors with nominal voltages between 380 V and 500 V. Resistance 13.4.3 Insulation The insulation resistance shall be measured across: a) all possible pairs of live parts or windings; b) all live parts and any other metallic parts suchas the core, case or mounting screws. The insulation resistance shall be not less than 20 Ma tier the application of 500 V dc applied for a sufficient length of time for the reading to become steady. 13.5 Type Tests 13.5.1 Schedule of Type Tests All inductors for type tests shall have successfully met the routine tests of 13.4. The inductors shall then be checked for conformity with the specified dimensions. In addition, if the inductors are of non-metallic construction, a metal foil shall be closely wrapped around the inductor to within 5 mm of any IS 14479 : 1998 exposed live part, the test voltage shall be applied between this foil and the winding without any breakdown. A total of 14 inductors shall then be tested in the following order: Lot A five inductors) Voltage drop conditions. Self-capacitance `Q' at self-resonance Robustness of terminations Soldering Vibration Bumping Climatic sequence: dry heat damp heat (accelerated) cold damp heat (accelerated) (remaining cycles) (first cycle) under maximum loading Cross-Sectional Area of Wire (mm21 Exceeding 0.5 Exceeding 0.2 up to and including 0.5 Up to and including 0.2 Test Ub (Bending) Two consecutive bends shall be applied to two samples without fracture. Test UC (Torsion) Two consecutive rotations severity 2 are to be applied to the three remaining samples without fracture. Test Ud (Torque for Threaded Terminations) A torque as set out in the following table shall be applied: Thread Diameter (mm) 3.0 3.5 4.0 5.0 Final measurements. Lot B @ve inductors) Damp heat (long term). Lot C (two inductors) Qvercurrent and heating. Lot D (two inductors) Short circuit. 13.5.2 Robustness of Terminations The requirements of vibration test of IS 9000 (Part 8) shall be met with a specified severity 4. 13.5.5 Bumping Test Uai, Ub, Ud shall be met as applicable. Test Ua, (Tensile Stress) For all types of terminations except wire terminations, apply a force of 20 N. For wire terminations, as in the following table: 23 The requirements of bump test as given in Section 2 of IS ~9000 (Part 7;IISec 1 to 5) shall be met. 13.5.6 Dry Heat The requirements of-IS 9000 (Part 3/Set 1 to 5) shall be met. 5.5 6.0 8.0 There shall be no visual damage. 13.5.3 Soldering Soldering terminations shall meet the requirements of IS 3723 (Part 1). Alternatively, the solder globule test of I§ 9000 (Part 1USec 1 to 3) shall be complied with. 13.5.4 Vibration The requirements for robustness of terminations as given in IS 9000 (Part 19/Set 1 to 5). Torque (Nm) 0.5 0.75 1.0 1.5 2.0 2.5 3.0 Force (N) 20 10 5 IS 14479 : 1998 13.57 Damp Heat (Accelerated) (First Cycle) conductivity shall remain unimpaired. 14 SPECIAL REQUIREMENTS FOR FILTERS The requirements of damp heat (first cycle) test of IS 9000 (Part S/Set 1 and 2) shall be met. 13.5.8 Cold Test The requirements of test of IS 9000 (Part Z/Set 1 to 4) shall be met as for - 55°C components. 13.5.9 Drop Heat (Accelerated) Cycles) (Remaining 14.1 Assemblies of inductors and/or capacitors in a common container are classed as filters. Such filters may be either open or sealed. If the filters are open, their components shall individually meet the requirements of the sections of this publication relevant to these components. If the filters are sealed, then they shall: either include only components which individually meet the requirements of the sections of this publication relevant to those components, and or include components which individually do not meet the requirements of the sections of this publication relevant to those components. In this case, the filter shall conform with the type tests shown in this section. The requirements of the accelerated damp heat (remaining cycles) test of IS 9000 (Part S/Set 1 and 5) shall be met with severity of cycles. 13.5.10 Final Measurements There shall be no damage at the conclusion of these tests. The inductance, voltage proof and insulation resistance checks shall be repeated and the results still meet the original specifications. 13.5.11 Damp Heat (Long Term) The requirements of damp heat (long term) test of IS 9000 (Part 4) shall be met for a 56-day exposure. There shall be no damage at the conclusion of these tests. The inductance, voltage proof and insulation resistance checks shall again be carried out and the results still meet the original specifications. 13.5.12 Overcurrent and Temperature Rise The inductors shall be raised to their maximum operating temperature and 1.1 times the nominal current passe-d through until a~final steady temperature is reached. The maximum temperature of the insulation shall then not exceed that appropriate to the class of insulation used. The voltage test shall be applied without breakdown whilst inductors are at their maximum steady temperature. Upon cooling, the inductors shall pass the self-endurance and insulation tests. 13.5.13 Short-Circuit The inductors shall withstand,without exploding or catching fire, a current of ten times the nominal current applied for 20 mm. In the caseof inductors intended for use in earth leads, the voltage drop measured across the inductor termimals under the above condition shall not exceed 50 V. After this test, the insulation resistance shall be measured and shall be greater than 20 M a. The 24 - 14.2 Marking The following marking information in the order given is required: a) Nominal current; b) Maximum voltage and power frequency range; c) Maximum operating temperature; 4 Indication of the correct method connection with a circuit diagram; of e) Manufacturer's name or trade-mark; 0 Manufacturer's type designation or catalogue number; g) Year of manufacture, clearly indicated (use of code is not permitted); and I.0 Reference to Indian Standard specification appropriate to the filter. 14.3 Routine 14.3.1 Tests Voltage Proof All filters shall withstand without breakdown or flashover a test voltage of 1 500 V (rms) at 50 Hz or 60 Hz applied for 1 s between: a) all terminals connected together and any other accessible metallic parts such as on the case or mounting screws; and IS 14479 : 1998 b) where the case is non-metallic, a metal foil shall be closely wrapped around the body of the case within 5 mm of any exposed live parts or terminations. The test voltage shall be applied between the foil and the live parts or terminals connected together. 14.3.2 Insulation Resistance Test Ub Two connective bends shall be applied to half the terminations without fracture. Test UC Two successive rotations severity 2 shall be applied to half the termination without fracture. Test Ud (Threaded Terminations) The insulation resistance shall be measured at 500 V (dc). The measured value of resistance shall not be less than 20 M n. 14.4 Type Tests 14.4.1 Schedule of Type Tests A torque as set out in the following table shall be applied: Thread Diameter (mm) 3.0 3.5 4.0 5.0 5.5 6.0 8.0 Torque (Nm) 0.5 0.75 It is intended that all components in filter assemblies shall be subjected to all the relevant type tests. Such checks may, however, be carried out on individual components before assembly or through accessible terminations on the filter unit after assembly. All filters submitted to type tests shall have successfully met the routine tests of 14.3. A lot comprising two samples shall be submitted to the following tests. 14.4.2 Radio-Frequency Characteristics 1.0 1.5 2.0 2.5 3.0 There shall be no visual damage. 14.4.4 Soldering The manufacturer shall determine and provide the insertion less curve over the operating frequency range of the filter when determined by a method similar to that described for capacitors in IS 3723 (Part 1). 14.4.3 Robustness of Terminations Filters provided with soldering terminations shall be subjected to tests of IS 9000 (Part 18/Set 1 to 3) using soldering-iron method size a. Alternatively, the solder globule test shall be met. 14.4.5 Mbration The filters shall be subjected to tests Ua, Ub, UC and Ud of IS 9000 (Part 19/Set 1 to 5) as applicable. Test Ua The requirements of IS 9000 (Part 18) shall be met with a specified severity. 14.4.6 Bumping The requirements of IS 9000 (Part 7/Set 2) shall be met. 14.4.7 Dry Heat The requirements shall be met. 14.4.8 Accelerated of IS 9000 (Part 3/Set 1 to 5) Damp Heat (First Cycle) For all types of terminations except wire terminations, supply a force of 20 N. For wire terminations, Cross-Sectional (mm21 as in the following table: Force (N) Area of Wire Exceeding 0.5 Exceeding 0.2 up to and including 0.5 Up to and including 0.2 20 10 The requirements of accelerated damp heat (first cycle) of IS 9000 (Part S/Set 1 and 2) shall be met with severity 4. 14.4.9 Cold 5 25 The requirement of IS 9000 (Part 2/Set 1 to 4) shall be met. 1s 14479 : 1998 14.4.10 Accelerated Damp Heat (Remaining Cycles) The requirements of IS 9000 (Part S/Set 1 and 2) shall be met with severity 4 (live cycles). 14.4.11 Damp sion of the type tests, the insertion loss curve shall be-determined and it shall not have changed significantly. 15 REQUIREMENTS CAPACITORS FOR FUSES USED FOR Heat (Long Term) 15.1 Allfuses and connections shall be so designed that their impedance to radio frequencies is as small as possible. The requirements of IS 9000 (Part 4) shall be met for a %-day exposure. 14.4.12 Temperature Rise 15.2 To minimize the effects of impedance, fuses shall only be used in the live leads. 15.3 Fuses shall withstand the change or discharge currents from associated capacitors, under any conditions. 15.4 A fuse shall operate under any short-circuit current due to the failure of the associated capacitor and shall comply with the requirements of IS 10242 (Part 2/&c 2). 15.5 Fuses shall be selected in accordance with the principles set out in IS 10242 (Part 2/Set 2). 15.6 Fuses forming part of a capacitor assembly shall be included in all tests for capacitors. The filter shall be raised to a steady temperature by the passage of its nominal current and the internal temperature rise determined by the change of resistance. The total temperature, taking into account the ambient temperature shall not exceed the minimum rated temperature of the insulating material or capacitors. The voltage-proof test shall then be applied without breaking, while the filter is at its maximum steady temperature. 144.13 Type Test Results The filters shall be examined after each type test and there shall be no visible damage. At the conclu- 126 IS 14479 : 1998 ANNEX A ( Clause 2 ) LIST OF INDIAN STANDARDS IS No. Title IS No. Title 3723 (Part 1) : 1978 Specification for capacitors for radio interference suppression : Part 1 General requirements and methods of tests ( first revision ) Section ( prst 1 Test Ua, : Tensile revision ) : Section 2 Test Ua, ( first revision ) Thrust 9000 Basic environmental testing procedures for electronic and electrical items Cold test Dry heat test Damp heat (steady state) 10052 (Part 1) : 1982 Section 3 Test Ub : Bending ( first revision ) Section 4 Test UC : Torsion ( first revision ) Section (first (Part 2/Set 1 to 4) : 1977 (Part 3/Set 1 to 5) : 1977 (Part 4) : 1979 5 Test Ud : Torque revision ) (Part S/Set 1 Damp heat (cyclic test) and 2) : 1981 (Part 7lSec 1 to 5) 1979 (Part 8) : 1981 Impact test Vibration (sinusoidal) test 10242 (Part 2/Set 2) : 1983 interference Electromagnetic apparatus and measuring measurement methods : Part 1 Measuring apparatus in the frequency range 10 kHz to 1 GHz electrical Specification for installations in ships Part 2 System production (Part 10) : 1979 Mould growth test (Part 11) : 1983 Salt mist test (Part 1USec 1 to 3) : 1988 (Part lS/Sec 1 to 9) : 1988 (Part 1USec 1 to 3) : 1981 (Part 19/Set 1 to 5) : 1986 Test N change of temperature (first revision ) Sealing test Solderability test electrical Specification for 10242 in ships : Part 3 (Part 3/Set 12) installations Equipment, Section 12 Choice and : 1986 installation of cables for low voltage systems 12193 (Part 2) : 1987 Methods of measurement for radio receivers for various classes of emission : Part 2 Radio measurements on frequency for amplitude receivers Modulated sound broadcast emissions Test U robustness of terminations and integral mounting devices 27 Bureau of Indian Standards BIS is a statutory institution established under the Bureau ofhdian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters in the country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed to the Director (Publications), BIS. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed periodically; a standard along with amendments is reaffirmed when such review indicates that no changes are needed; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standards should ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of `BIS Handbook' and `Standards : Monthly Additions'. This Indian Standard has been developed from Dot : No. ET 26 (3 287). 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